bob urz wrote:

Having owned many of these, i often wondered on how to get
the most lifetime out of the battery's.

I have had little used 14.4 volt drills that after 2 or 3
years the battery packs become very degraded. I this case,
the drill sits unused for a long period of time, then recharged
before next use.

Laptops, same story. occasional use, sits for awhile then used again.

Batteries are usually rated for so many cycles of recharging.
So, should it be better to constantly recharge the units,
or only charge as needed?

The charge as needed method for units that sit for awhile does not
seem to work out very well. I have a number of drill power packs
that i need to find some of those tab ni-cads for. I think there
c size or such. Anybody with tips on that let me know..

Keeping them constantly plugged in seems to me would use up
there number of charge cycles and shorten life to.

so, whats the best way to get the most out of rechargeable battery
packs?

And how can hybrid cars get 10 years out of a battery pack
when i am lucky to get 2 or 3 out of most of the packs i have?
I do see online how some of the early gen Prius packs are failing
much to the owners displeasure.

The Prius maintains its batteries at between 50-80% of full charge.

Any new battery or battery that's gone unused for at least 2 months
should be charged longer than normal, 24-36 hours, whether you use a
fast charger or trickle charger. The only exceptions are very
primitive chargers that end charging with just a simple bimetal
thermostat. Disconnect the battery within an hour after the
thermostat opens.

Try to let batteries cool down before recharging, but do not leave the
battery connected to the battery continuously, even if the charger is
designed to shut off or go into a maintenance mode. Also do not fully
discharge batteries regularly but only down to 1.1V per cell (13.2V,
in the case of a 14.4V battery). Deeper discharge is harmful. Also
check each cell occasionally for reverse polarity. If not corrected,
reverse polarity will lead to the affected cell becoming shorted and
the other cells overcharged. To correct reverse polarity, charge the
affected cell by directly connecting approximately 100mA DC to that
cell and only that cell for a few minutes, then recharge the battery
normally.

Drilling several tiny vent holes into the battery pack may help
cooling, top and bottom, but remove the cells first.